In a motor having a stator and a rotor within a case, in order to connect a lead wire of a coil of the stator to an external control device, it is necessary for the lead wire to extend out of the case through a through hole of the case. When such a structure is used, a foreign substance may enter the case from outside of the case through the through hole, thereby, causing an adverse effect on the operation of the motor.
In coping with such a situation, a patent document 1 (i.e., Japanese Patent Laid-Open No. H11-89156) discloses the following structure, in which a seal member is provided which is made of rubber and has a ring part that engages with an entire edge of the through hole of the case. The seal member also includes a cork part that engages an inner wall of the ring part and has a hole for inserting the lead wire. As such, the seal member seals the through hole of the case.
If a driver apparatus having a one-body structure of a motor and its control unit for the control of the motor is taken into consideration, the lead wire of the coil of the stator in the motor extends through the through hole of the case of the motor to an outside of the case, and is connected to the control unit. Then, for sealing the through hole of the case, a seal member as described in patent document 1 may be used.
However, in order to install/assemble such a seal member, the ring part is disposed in the through hole of the case while being first deformed, and then the cork part is engaged with an inside of the ring part while having the lead inserted thereinto. Further, assembly must be performed manually by hand. Therefore, attachment of the seal member takes time and is difficult to automate.